472 HABITATIONS OF INSECTS. 



This door the ingenious artist fixes to the entrance of 

 her gallery by a hinge of silk, which plays with the 

 greatest freedom, and allows it to be opened and shut 

 with ease; and as if acquainted with the laws of gravity, 

 she invariably fixes the hinge at the highest side of the 

 opening, so that the door when pushed up shuts again 

 - by its own weight. She has not less sagaciously left a 

 little edge or groove just within the entrance, upon which 

 the door closes, and to which it fits with such precision, 

 that it seems to make but one surface with it. Such is 

 the astonishing structure of this little animal's abode ; 

 nor is its defence of its subterraneous cavern less sur- 

 prising. If an observer adroitly insinuates the point of 

 a pin under the edge of the door, and elevates it a little, 

 he immediately perceives a very strong resistance. — 

 What is its cause ? — The spider, warned by the vibra- 

 tions of the threads which extend from the door to the 

 bottom of her gallery, runs with all speed to the door, 

 fastens its legs to it on one side, and on the other to the 

 walls, and, turning upon its back, pulls with all its might. 

 Thus the door is alternately shut or opened, as the exer- 

 tions of the observer or of the spider prevail. It is easy 

 to guess which will in the end conquer ; and the spider, 

 when it finds all resistance ineffectual, betakes itself to 

 flight, and retreats. If, to make a further experiment, 

 the observer fastens down the door so that it cannot be 

 forced open, the next morning he will find a new en- 

 trance, with a new door formed at a small distance ; or, 

 if he take the door entirely away, another will be con- 

 structed in less than twelve hours. 



The habitation thus singularly formed and defended 



